The present invention refers to a method and assisting devices intended to be used to sense the breathing of a man or an animal.
With xe2x80x9cto sense breathingxe2x80x9d in this document is referred primarily to achieve a signal which to a substantial extent follows the breathing air flow.
In connection to utilization of an equipment to sense breathing according to the international patent application WO 94/16620 a breathing sensor should be placed so that it is located in the breathing air flow at exhaling as well as inhaling. This is exemplified in the application by a retainer that is applied in a nostril.
A problem that is solved by the present invention, is by means of a breathing sensor to reliably sense the breathing regardless of whether it occurs through the nose or mouth. Another problem that is solved is to securely hold the breathing sensor in its position and simply be able to apply and remove the same. Moreover it should be possible to move the sensor from one patient to another without a risk of transmisson of infection. A further problem that is solved is to give small influence on normal breathing. These and other problems are solved by a method and devices according to the following patent claims.
In the first place thus a device is used that conducts breathing air flows to and from the nose as well as the mouth past a position at which the sensor is placed so that breathing detection may take place irrespective of how breathing occurs.
In a first embodiment a tubular device is used that is fixed between and with an end orifice at each of the nose and mouth and a third orifice of the sensor placed on the tubular device. This embodiment includes three main parts: the tubular device, a fastening plate for the tubular device and a sensor retainer which can be fastened to the device by snap action. A second embodiment is constituted mainly by a convexly rounded part intended to be fastened above the nose and mouth together with the first embodiment and formed such that it captures the breathing air flows and leads them to the orifice of the sensor. The tubular as well as the convexly rounded part are designed such that they do not constitute any obstruction for normal breathing. A variant of the convexly rounded part is provided to be able to be used together with a nasal canula. The sensor retainer according to the invention can also be used for patients that have been intubated, whereby a special intermediate part with a connection tube piece for the sensor retainer is used.
In a third embodiment, the tubular device is externally shaped with a flattened portion which is provided with adhesive means so that a special fixing plate is not required to fasten the tubular device to the upper lip. This embodiment can also be designed to be directly fastened to a nasal canula without requirement of the convexly rounded part according to the second embodiment.
The devices according to the invention not only may be used with an equipment of the type mentioned above that utilizes a fibre end in the breathing air flow, but also together with other breathing sensors intended to be placed in breathing air flow, for example such being based on temperature sensing.
Devices that utilize hoses to conduct air flows from nose and mouth respectively to a common breathing sensor are known through WO 9641571 A (FIG. 8a, claims 1-10) and WO 9705824 Al (FIG. 5). Moreover, devices with several sensors for sensing mouth and nose breathing are known through the above references, as well as U.S. Pat. No. 5,069,222 A and U.S. Pat. No. 5,413,111 A.